About MBeans:

MBeans, short form of MangedBeans are used to represent the resources in jvm, java applications and application servers through java objects. So, with the combination of JMX (Java programming APIs) and MBeans (java objects that are representing the resources such as Transaction monitors, JDBC Drivers and Printers and many more) we can collect/extract statistics related to performance, resource usages, and many more for the resources running in JVM. Refer the Wiki: http://en.wikipedia.org/wiki/Java_Management_Extensions#Managed_Bean